【C言語】Artistic Style（AStyle）でコードの整形を

悩んでいる人

おすすめのC言語のコード整形ツールを教えて！

こういった悩みにお答えします．

本記事の信頼性

リアルタイムシステムの研究歴12年．
東大教員の時に，英語でOS（Linuxカーネル）の授業．
2012年9月～2013年8月にアメリカのノースカロライナ大学チャペルヒル校（UNC）コンピュータサイエンス学部で客員研究員として勤務．C言語でリアルタイムLinuxの研究開発．
プログラミング歴15年以上，習得している言語: C/C++，Python，Solidity/Vyper，Java，Ruby，Go，Rust，D，HTML/CSS/JS/PHP，MATLAB，Assembler (x64，ARM)．
東大教員の時に，C++言語で開発した「LLVMコンパイラの拡張」，C言語で開発した独自のリアルタイムOS「Mcube Kernel」をGitHubにオープンソースとして公開．
2020年1月～現在はアメリカのノースカロライナ州チャペルヒルにあるGuarantee Happiness LLCのCTOとしてECサイト開発やWeb/SNSマーケティングの業務．2022年6月～現在はアメリカのノースカロライナ州チャペルヒルにあるJapanese Tar Heel, Inc.のCEO兼CTO．
最近は自然言語処理AIとイーサリアムに関する有益な情報発信に従事．

（AI全般を含む）自然言語処理AIの論文の日本語訳や，AIチャットボット（ChatGPT，Auto-GPT，Gemini（旧Bard）など）の記事を50本以上執筆．アメリカのサンフランシスコ（広義のシリコンバレー）の会社でプロンプトエンジニア・マネージャー・Quality Assurance（QA）の業務委託の経験あり．
（スマートコントラクトのプログラミングを含む）イーサリアムや仮想通貨全般の記事を200本以上執筆．イギリスのロンドンの会社で仮想通貨の英語の記事を日本語に翻訳する業務委託の経験あり．

こういった私が解説していきます．

C言語を独学で習得することは難しいです．

私にC言語の無料相談をしたいあなたは，公式LINE「ChishiroのC言語」の友だち追加をお願い致します．

私のキャパシティもあり，一定数に達したら終了しますので，今すぐ追加しましょう！

独学が難しいあなたは，元東大教員がおすすめするC言語を学べるオンラインプログラミングスクール5社で自分に合うスクールを見つけましょう．後悔はさせません！

: 元東大教員がおすすめするC言語を学べるオンラインプログラミングスクール5社

こういった悩みにお答えします．こういった私が解説していきます．私が大学の授業で初めてC言語を勉強した時は全然できませんでしたが，先生やTA，友人に相談しながら一生懸命C言語を勉強してできるようにな ...

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Artistic Style（AStyle）

Artistic Style（AStyle）はC言語で利用可能なコード整形ツールです．

また，C++言語，Objective‑C言語，C#言語，Java言語に対応しています．

AStyleでは，主に以下のポイントで整形します．

ブラケットスタイル
インデント
括弧
パディング
フォーマット
その他（サブディレクトリを再帰的に処理したい場合，処理から除外したい場合等に設定）

私がC言語でコードを書く時は，AStyleを利用してコードを整形します．

AStyleにより同じコーディングスタイルでコードを記述することで，コードの可読性や移植性が向上します．

特にチーム開発で有用ですので，C言語のコードを是非AStyleで整形しましょう．

AStyleは，Debian/Ubuntuではapt-get，Fedora/CentOS/RedHatではdnfで簡単にインストールできます．

$ sudo apt-get install astyle # dnf install astyle // Fedora/CentOS/RedHat

1	$ sudo apt-get install astyle # dnf install astyle // Fedora/CentOS/RedHat

私のAStyleの設定ファイル「astylerc」

私のAStyleの設定ファイル「astylerc」は以下になります．是非，参考にして下さい．

全ての設定のオプションは，こちらの記事に書いてあります．

#
# AStyle for C language
#
# Hiroyuki Chishiro
#

# "One True Brace Style" uses linux braces and adds braces to unbraced
# one line conditional statements. Opening braces are broken from
# namespaces, classes, and function definitions. The braces are attached
# to everything else, including arrays, structs, enums, and statements
# within a function.
style=1tbs

# Indent using # spaces per indent (e.g. -s3 --indent=spaces=3). #
# must be between 2 and 20. Not specifying # will result in a default of
# 4 spaces per indent.
indent=spaces=2

# Pad empty lines around header blocks (e.g. 'if', 'for', 'while'...).
break-blocks

# Insert space padding around operators. This will also pad
# commas. Any end of line comments will remain in the original column,
# if possible. Note that there is no option to unpad. Once padded, they
# stay padded.
pad-oper

# Insert space padding after commas. This is not needed if pad-oper is
# used. Any end of line comments will remain in the original column, if
# possible. Note that there is no option to unpad. Once padded, they
# stay padded.
pad-comma

# Insert space padding between a header (e.g. 'if', 'for', 'while'...)
# and the following paren. Any end of line comments will remain in the
# original column, if possible. This can be used with unpad-paren to
# remove unwanted spaces.
pad-header

# Remove extra space padding around parens on the inside and
# outside. Any end of line comments will remain in the original column,
# if possible. This option can be used in combination with the paren
# padding options pad-paren, pad-paren-out, pad-paren-in, and pad-header
# above. Only padding that has not been requested by other options will
# be removed.

# For example, if a source has parens padded on both the inside and
# outside, and you want inside only. You need to use unpad-paren to
# remove the outside padding, and pad-paren-in to retain the inside
# padding. Using only pad-paren-in> would not remove the outside
# padding.
unpad-paren

# Attach a pointer or reference operator (*, &, or ^) to either the
# variable type (left) or variable name (right), or place it between the
# type and name (middle). The spacing between the type and name will be
# preserved, if possible. This option is for C/C++, C++/CLI, and C#
# files. To format references separately, use the following
# align-reference option.
align-pointer=name

# This option will align references separate from pointers. Pointers are
# not changed by this option. If pointers and references are to be
# aligned the same, use the previous align-pointer option. The option
# align-reference=none will not change the reference alignment. The
# other options are the same as for align-pointer. This option is for
# C/C++, C++/CLI, and C# files.
align-reference=name

# Break one line headers (e.g. 'if', 'while', 'else', ...) from a
# statement residing on the same line. If the statement is enclosed in
# braces, the braces will be formatted according to the requested
# brace style.
# A multi-statement line will NOT be broken if keep-one-line-statements
# is requested. One line blocks will NOT be broken if
# keep-one-line-blocks is requested and the header is enclosed in the
# block.
break-one-line-headers

# Add braces to unbraced one line conditional statements (e.g. 'if',
# 'for', 'while'...). The statement must be on a single line. The
# braces will be added according to the requested brace style. If no
# style is requested the braces will be attached.
# Braces will NOT be added to a multi-statement line if
# keep-one-line-statements is requested. Braces will NOT be added to a
# one line block if keep-one-line-blocks is requested. If used with
# --add-one-line-braces, the result will be one line braces.
add-braces

# Indent C++ comments beginning in column one. By default C++ comments
# beginning in column one are assumed to be commented-out code and not
# indented. This option will allow the comments to be indented with the
# code.
indent-col1-comments

# Attach the return type to the function name. The two options are for
# the function definitions (-xf), and the function declarations or
# signatures (-xh). They are intended to undo the --break-return-type
# options. If used with --break-return-type, the result will be to
# break the return type. This option has no effect on Objective-C functions.
attach-return-type
attach-return-type-decl

# The option max-code-length will break a line if the code exceeds #
# characters. The valid values are 50 thru 200. Lines without logical
# conditionals will break on a logical conditional (||, &&, ...),
# comma, paren, semicolon, or space.
# Some code will not be broken, such as comments, quotes, and arrays. If
# used with keep-one-line-blocks or add-one-line-braces the blocks will
# NOT be broken. If used with keep-one-line-statements the statements
# will be broken at a semicolon if the line goes over the maximum
# length. If there is no available break point within the max code
# length, the line will be broken at the first available break point
# after the max code length.
# By default logical conditionals will be placed first in the new
# line. The option break-after-logical will cause the logical
# conditionals to be placed last on the previous line. This option has
# no effect without max-code-length.
max-code-length=80
break-after-logical

max-continuation-indent=80

# Indent a C type, C#, or Java file. C type files are C, C++, C++/CLI,
# and Objective-C. The option is usually set from the file extension
# for each file. You can override the setting with this entry. It will
# be used for all files, regardless of the file extension. It allows
# the formatter to identify language specific syntax such as C++
# classes, templates, and keywords.
mode=c

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# AStyle for C language

# Hiroyuki Chishiro

# "One True Brace Style" uses linux braces and adds braces to unbraced

# one line conditional statements. Opening braces are broken from

# namespaces, classes, and function definitions. The braces are attached

# to everything else, including arrays, structs, enums, and statements

# within a function.

style=1tbs

# Indent using # spaces per indent (e.g. -s3 --indent=spaces=3). #

# must be between 2 and 20. Not specifying # will result in a default of

# 4 spaces per indent.

indent=spaces=2

# Pad empty lines around header blocks (e.g. 'if', 'for', 'while'...).

break-blocks

# Insert space padding around operators. This will also pad

# commas. Any end of line comments will remain in the original column,

# if possible. Note that there is no option to unpad. Once padded, they

# stay padded.

pad-oper

# Insert space padding after commas. This is not needed if pad-oper is

# used. Any end of line comments will remain in the original column, if

# possible. Note that there is no option to unpad. Once padded, they

# stay padded.

pad-comma

# Insert space padding between a header (e.g. 'if', 'for', 'while'...)

# and the following paren. Any end of line comments will remain in the

# original column, if possible. This can be used with unpad-paren to

# remove unwanted spaces.

pad-header

# Remove extra space padding around parens on the inside and

# outside. Any end of line comments will remain in the original column,

# if possible. This option can be used in combination with the paren

# padding options pad-paren, pad-paren-out, pad-paren-in, and pad-header

# above. Only padding that has not been requested by other options will

# be removed.

# For example, if a source has parens padded on both the inside and

# outside, and you want inside only. You need to use unpad-paren to

# remove the outside padding, and pad-paren-in to retain the inside

# padding. Using only pad-paren-in> would not remove the outside

# padding.

unpad-paren

# Attach a pointer or reference operator (*, &, or ^) to either the

# variable type (left) or variable name (right), or place it between the

# type and name (middle). The spacing between the type and name will be

# preserved, if possible. This option is for C/C++, C++/CLI, and C#

# files. To format references separately, use the following

# align-reference option.

align-pointer=name

# This option will align references separate from pointers. Pointers are

# not changed by this option. If pointers and references are to be

# aligned the same, use the previous align-pointer option. The option

# align-reference=none will not change the reference alignment. The

# other options are the same as for align-pointer. This option is for

# C/C++, C++/CLI, and C# files.

align-reference=name

# Break one line headers (e.g. 'if', 'while', 'else', ...) from a

# statement residing on the same line. If the statement is enclosed in

# braces, the braces will be formatted according to the requested

# brace style.

# A multi-statement line will NOT be broken if keep-one-line-statements

# is requested. One line blocks will NOT be broken if

# keep-one-line-blocks is requested and the header is enclosed in the

# block.

break-one-line-headers

# Add braces to unbraced one line conditional statements (e.g. 'if',

# 'for', 'while'...). The statement must be on a single line. The

# braces will be added according to the requested brace style. If no

# style is requested the braces will be attached.

# Braces will NOT be added to a multi-statement line if

# keep-one-line-statements is requested. Braces will NOT be added to a

# one line block if keep-one-line-blocks is requested. If used with

# --add-one-line-braces, the result will be one line braces.

add-braces

# Indent C++ comments beginning in column one. By default C++ comments

# beginning in column one are assumed to be commented-out code and not

# indented. This option will allow the comments to be indented with the

# code.

indent-col1-comments

# Attach the return type to the function name. The two options are for

# the function definitions (-xf), and the function declarations or

# signatures (-xh). They are intended to undo the --break-return-type

# options. If used with --break-return-type, the result will be to

# break the return type. This option has no effect on Objective-C functions.

attach-return-type

attach-return-type-decl

# The option max-code-length will break a line if the code exceeds #

# characters. The valid values are 50 thru 200. Lines without logical

# conditionals will break on a logical conditional (||, &&, ...),

# comma, paren, semicolon, or space.

# Some code will not be broken, such as comments, quotes, and arrays. If

# used with keep-one-line-blocks or add-one-line-braces the blocks will

# NOT be broken. If used with keep-one-line-statements the statements

# will be broken at a semicolon if the line goes over the maximum

# length. If there is no available break point within the max code

# length, the line will be broken at the first available break point

# after the max code length.

# By default logical conditionals will be placed first in the new

# line. The option break-after-logical will cause the logical

# conditionals to be placed last on the previous line. This option has

# no effect without max-code-length.

max-code-length=80

break-after-logical

max-continuation-indent=80

# Indent a C type, C#, or Java file. C type files are C, C++, C++/CLI,

# and Objective-C. The option is usually set from the file extension

# for each file. You can override the setting with this entry. It will

# be used for all files, regardless of the file extension. It allows

# the formatter to identify language specific syntax such as C++

# classes, templates, and keywords.

mode=c

AStyleの利用例

AStyleの利用例として，以下のC言語のコードを整形します．

9～10行目にインデントがなくて読みにくいですね．．．

/*
 * Author: Hiroyuki Chishiro
 * License: 2-Clause BSD
 */
#include <stdio.h>

int main(void)
{
printf("Hello World!\n");
return 0;
}

* Author: Hiroyuki Chishiro

* License: 2-Clause BSD

#include <stdio.h>

int main(void)

{

printf("Hello World!\n");

return 0;

}

以下のコマンドでAStyleを実行して，C言語のコードを整形しましょう！

※AStyleの設定ファイル「astylerc」は，私の設定ファイルと同じ内容で，同じディレクトリに保存されているとします．

$ astyle astyle.c --options=astylerc

1	$ astyle astyle.c --options=astylerc

整形したコードは以下になります．

9～10行目にインデントが入って読みやすくなりました．

/*
 * Author: Hiroyuki Chishiro
 * License: 2-Clause BSD
 */
#include <stdio.h>

int main(void)
{
  printf("Hello World!\n");
  return 0;
}

* Author: Hiroyuki Chishiro

* License: 2-Clause BSD

#include <stdio.h>

int main(void)

{

printf("Hello World!\n");

return 0;

}

AStyleによるインデントの調整を無効にする方法

AStyleによるインデントの調整を無効にする方法は，以下のように無効にしたい部分のコードを「/* *INDENT-OFF* */」と「/* *INDENT-ON* */」で挟みます．

/*
 * Author: Hiroyuki Chishiro
 * License: 2-Clause BSD
 */
#include <stdio.h>

int main(void)
{
/* *INDENT-OFF* */
printf("Hello World!\n");
return 0;
/* *INDENT-ON* */
}

* Author: Hiroyuki Chishiro

* License: 2-Clause BSD

#include <stdio.h>

int main(void)

{

/* *INDENT-OFF* */

printf("Hello World!\n");

return 0;

/* *INDENT-ON* */

}

以下のコマンドでAStyleを実行した場合，インデントの調整が無効になることがわかります．

$ astyle astyle2.c --options=astylerc

1	$ astyle astyle2.c --options=astylerc

参考：C++言語のコードの整形はclang-formatがおすすめ

参考までに，C++言語のコードの整形はclang-formatがおすすめです！

clang-formatの使い方は以下の記事がわかりやすいです．

私のclang-formatの設定ファイル.clang-formatは以下になります．

---
Language:        Cpp
# BasedOnStyle:  Google
AccessModifierOffset: -1
AlignAfterOpenBracket: Align
AlignConsecutiveAssignments: false
AlignConsecutiveDeclarations: false
AlignEscapedNewlines: Left
AlignOperands:   true
AlignTrailingComments: true
AllowAllParametersOfDeclarationOnNextLine: true
AllowShortBlocksOnASingleLine: false
AllowShortCaseLabelsOnASingleLine: false
AllowShortFunctionsOnASingleLine: All
AllowShortIfStatementsOnASingleLine: true
AllowShortLoopsOnASingleLine: true
AlwaysBreakAfterDefinitionReturnType: None
AlwaysBreakAfterReturnType: None
AlwaysBreakBeforeMultilineStrings: true
AlwaysBreakTemplateDeclarations: true
BinPackArguments: true
BinPackParameters: true
BraceWrapping:   
  AfterClass:      false
  AfterControlStatement: false
  AfterEnum:       false
  AfterFunction:   true
  AfterNamespace:  false
  AfterObjCDeclaration: false
  AfterStruct:     false
  AfterUnion:      false
  AfterExternBlock: false
  BeforeCatch:     false
  BeforeElse:      false
  IndentBraces:    false
  SplitEmptyFunction: true
  SplitEmptyRecord: true
  SplitEmptyNamespace: true
BreakBeforeBinaryOperators: None
BreakBeforeBraces: Custom
BreakBeforeInheritanceComma: false
BreakBeforeTernaryOperators: true
BreakConstructorInitializersBeforeComma: false
BreakConstructorInitializers: BeforeColon
BreakAfterJavaFieldAnnotations: false
BreakStringLiterals: true
ColumnLimit:     80
CommentPragmas:  '^ IWYU pragma:'
CompactNamespaces: false
ConstructorInitializerAllOnOneLineOrOnePerLine: true
ConstructorInitializerIndentWidth: 2
ContinuationIndentWidth: 2
Cpp11BracedListStyle: true
DerivePointerAlignment: true
DisableFormat:   false
ExperimentalAutoDetectBinPacking: false
FixNamespaceComments: true
ForEachMacros:   
  - foreach
  - Q_FOREACH
  - BOOST_FOREACH
IncludeBlocks:   Preserve
IncludeCategories: 
  - Regex:           '^<ext/.*\.h>'
    Priority:        2
  - Regex:           '^<.*\.h>'
    Priority:        1
  - Regex:           '^<.*'
    Priority:        2
  - Regex:           '.*'
    Priority:        3
IncludeIsMainRegex: '([-_](test|unittest))?$'
IndentCaseLabels: true
IndentPPDirectives: None
IndentWidth:     2
IndentWrappedFunctionNames: false
JavaScriptQuotes: Leave
JavaScriptWrapImports: true
KeepEmptyLinesAtTheStartOfBlocks: false
MacroBlockBegin: ''
MacroBlockEnd:   ''
MaxEmptyLinesToKeep: 1
NamespaceIndentation: None
ObjCBlockIndentWidth: 2
ObjCSpaceAfterProperty: false
ObjCSpaceBeforeProtocolList: false
PenaltyBreakAssignment: 2
PenaltyBreakBeforeFirstCallParameter: 1
PenaltyBreakComment: 300
PenaltyBreakFirstLessLess: 120
PenaltyBreakString: 1000
PenaltyExcessCharacter: 1000000
PenaltyReturnTypeOnItsOwnLine: 200
PointerAlignment: Left
RawStringFormats:
- Language: TextProto
  Delimiters:
  - 'pb'
  - 'proto'
  BasedOnStyle: Google
ReflowComments:  true
SortIncludes:    true
SortUsingDeclarations: true
SpaceAfterCStyleCast: false
SpaceAfterTemplateKeyword: true
SpaceBeforeAssignmentOperators: true
SpaceBeforeParens: ControlStatements
SpaceInEmptyParentheses: false
SpacesBeforeTrailingComments: 2
SpacesInAngles:  false
SpacesInContainerLiterals: true
SpacesInCStyleCastParentheses: false
SpacesInParentheses: false
SpacesInSquareBrackets: false
Standard:        Auto
TabWidth:        2
UseTab:          Never
...

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---

Language: Cpp

# BasedOnStyle: Google

AccessModifierOffset: -1

AlignAfterOpenBracket: Align

AlignConsecutiveAssignments: false

AlignConsecutiveDeclarations: false

AlignEscapedNewlines: Left

AlignOperands: true

AlignTrailingComments: true

AllowAllParametersOfDeclarationOnNextLine: true

AllowShortBlocksOnASingleLine: false

AllowShortCaseLabelsOnASingleLine: false

AllowShortFunctionsOnASingleLine: All

AllowShortIfStatementsOnASingleLine: true

AllowShortLoopsOnASingleLine: true

AlwaysBreakAfterDefinitionReturnType: None

AlwaysBreakAfterReturnType: None

AlwaysBreakBeforeMultilineStrings: true

AlwaysBreakTemplateDeclarations: true

BinPackArguments: true

BinPackParameters: true

BraceWrapping:

AfterClass: false

AfterControlStatement: false

AfterEnum: false

AfterFunction: true

AfterNamespace: false

AfterObjCDeclaration: false

AfterStruct: false

AfterUnion: false

AfterExternBlock: false

BeforeCatch: false

BeforeElse: false

IndentBraces: false

SplitEmptyFunction: true

SplitEmptyRecord: true

SplitEmptyNamespace: true

BreakBeforeBinaryOperators: None

BreakBeforeBraces: Custom

BreakBeforeInheritanceComma: false

BreakBeforeTernaryOperators: true

BreakConstructorInitializersBeforeComma: false

BreakConstructorInitializers: BeforeColon

BreakAfterJavaFieldAnnotations: false

BreakStringLiterals: true

ColumnLimit: 80

CommentPragmas: '^ IWYU pragma:'

CompactNamespaces: false

ConstructorInitializerAllOnOneLineOrOnePerLine: true

ConstructorInitializerIndentWidth: 2

ContinuationIndentWidth: 2

Cpp11BracedListStyle: true

DerivePointerAlignment: true

DisableFormat: false

ExperimentalAutoDetectBinPacking: false

FixNamespaceComments: true

ForEachMacros:

- foreach

- Q_FOREACH

- BOOST_FOREACH

IncludeBlocks: Preserve

IncludeCategories:

- Regex: '^<ext/.*\.h>'

Priority: 2

- Regex: '^<.*\.h>'

Priority: 1

- Regex: '^<.*'

Priority: 2

- Regex: '.*'

Priority: 3

IncludeIsMainRegex: '([-_](test|unittest))?$'

IndentCaseLabels: true

IndentPPDirectives: None

IndentWidth: 2

IndentWrappedFunctionNames: false

JavaScriptQuotes: Leave

JavaScriptWrapImports: true

KeepEmptyLinesAtTheStartOfBlocks: false

MacroBlockBegin: ''

MacroBlockEnd: ''

MaxEmptyLinesToKeep: 1

NamespaceIndentation: None

ObjCBlockIndentWidth: 2

ObjCSpaceAfterProperty: false

ObjCSpaceBeforeProtocolList: false

PenaltyBreakAssignment: 2

PenaltyBreakBeforeFirstCallParameter: 1

PenaltyBreakComment: 300

PenaltyBreakFirstLessLess: 120

PenaltyBreakString: 1000

PenaltyExcessCharacter: 1000000

PenaltyReturnTypeOnItsOwnLine: 200

PointerAlignment: Left

RawStringFormats:

- Language: TextProto

Delimiters:

- 'pb'

- 'proto'

BasedOnStyle: Google

ReflowComments: true

SortIncludes: true

SortUsingDeclarations: true

SpaceAfterCStyleCast: false

SpaceAfterTemplateKeyword: true

SpaceBeforeAssignmentOperators: true

SpaceBeforeParens: ControlStatements

SpaceInEmptyParentheses: false

SpacesBeforeTrailingComments: 2

SpacesInAngles: false

SpacesInContainerLiterals: true

SpacesInCStyleCastParentheses: false

SpacesInParentheses: false

SpacesInSquareBrackets: false

Standard: Auto

TabWidth: 2

UseTab: Never

...

まとめ

C言語のコード整形ツールとしてAStyleを紹介しました．

また，私のAStyleの設定ファイルを公開していますので，C言語でコードを書く時の参考にしてください．

C言語を独学で習得することは難しいです．

私にC言語の無料相談をしたいあなたは，公式LINE「ChishiroのC言語」の友だち追加をお願い致します．

私のキャパシティもあり，一定数に達したら終了しますので，今すぐ追加しましょう！

: 元東大教員がおすすめするC言語を学べるオンラインプログラミングスクール5社

こういった悩みにお答えします．こういった私が解説していきます．私が大学の授業で初めてC言語を勉強した時は全然できませんでしたが，先生やTA，友人に相談しながら一生懸命C言語を勉強してできるようにな ...

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